Disposable apparatus for circle absorption system

ABSTRACT

A circle absorption system for anesthesia, including a gas machine, a carbon dioxide absorbing canister, a gas supply hose thereto, rebreathing hoses and a mask connected thereto, absorbing medium therein, and a four way coupling having a pair of one way directional valves, a bleed valve and an outlet for receiving a rebreathing bag. The canister is rectangular in configuration and has recessed fittings for receiving the various hoses. The canister has a plate-groove arrangement whereby the size of chambers within the canister may be readily controlled while allowing quick and easy assembly of the canister.

[451 Sept. 17, 1974 2,675,885 4/1954 Fox 55/387 DISPOSABLE APPARATUS FORCIRCLE ABSORPTION SYSTEM 75 I t I I D Primary ExaminerCharles N. Hart 1men or G8 e ryden lndlanapohs Ind Attorney, Agent, or Firm Woodard,Weikart,

Emhardt & Naughton [73] Assignee: Dryden Corporation, Indianapolis,

Ind.

[57] ABSTRACT A circle absorption system for anesthesia, including a[22] Filed: Jan. 31, 1973 gas machine, a carbon dioxide absorbingcanister, a gas supply hose thereto, rebreathing hoses and a maskconnected thereto, absorbing medium therein, and a four way couplinghaving a pair of one way directional valves, a bleed valve and an outletfor receiving a rebreathing bag. The canister is rectangular inconfiguration and has recessed fittings for receiving the vari- 7 w wwoo 8 5 8 7 m3 m m D. m m3 4 n 0 l H mm .w M m s WN mmm mmm l e H" 3 58mu" m m m mn mmfl O mm m m a L id C D. mn ..l D. om mh A Ca U-lF l. 11ll] 1 3 218 2 6 555 l. l. [ll

ous hoses. The canister has a plate-groove arrangement whereby the sizeof chambers within the canister may be readily controlled while allowingquick and easy assembly of the canister.

[56] References Cited UNITED STATES PATENTS 221333 3 Claims, 7 DrawingFigures 2,469,842 5/1949 Paguin et al. 2,614 56! 10/1952 0 9 a 0 I umpmmsm mu SHEEI 3' 0F 3.

Fig.6

INVENTOR GALE E. DRYDEN ATTORNEYS WWW-M Ward 4% DISPOSABLE APPARATUS FORCIRCLE ABSORPTION SYSTEM This is a continuation of application Ser. No.131,873, filed Apr. 7, 1971 and now abandoned.

BACKGROUND OF THE INVENTION 1. Field of the Invention This inventionrelates generally to anesthesia apparatus and more particularly to thecanister and fittings.

2. Description of the Prior Art As explained in my US. Pat. No.3,566,867 issued on Mar. 2, 1971, and my pending application Ser. No.775,761, filed Nov. 14, 1968, it is desirable to provide a low-cost anddisposable canister having absorbent material therein. Althoughconsiderable prior art has been cited in those applications, none havehad the expendable, disposable aspects which I consider necessary forsignificant improvement in safety for patients. As a result of furtherthought on this matter, I have some additional concepts as follows: As aresult of the disposable nature of the canister, a great number ofcanisters are transported. Thus, it is desirable for the fittings of thecanister to be recessed preventing damage thereof during thetransportation of the canister. In addition, it is desirable for thecanister to be rectangular in configuration in order to minimize thespace needed for the transportation of a plurality of canisters.

My canisters have three chambers, one of which has absorbent materialtherein. Depending upon the exact use requirements of the canister, theamount of absorbent material may be varied. Thus, the size of thechamber containing the absorbent material may be altered in accordancewith the use requirements. It can be appreciated that it is relativelyexpensive to produce a variety of canisters having different sizedchambers for receiving absorbent material. Thus, it is desirable toproduce a single canister body which will easily receive walls duringthe assembly of the canister in such a way that the size of the chambermay be varied. A canister disclosed herein has a main body which willreceive walls in such a way so that the size of the chamber may begreatly varied during the assembly of the canister.

SUMMARY OF THE INVENTION One embodiment of the invention disclosedherein is the combination comprising: rectangular container means havingfirst, second, and third chambers therein, said second chamber beingadjacent to said first and third chambers, a first recessed inletfitting in said container means communicating with said first chamber, afirst recessed outlet fitting in said container means communicating withsaid third chamber, said first chamber communicating with said thirdchamber through said second chamber, an absorbent material for carbondioxide disposed in said second chamber, a plurality of additionalrecessed fittings in said container means communicating with saidchambers, and a removable, valved coupling all of which is disposable asa unit. This disposable unit is employed with a conventional anesthesiamachine having means receiving said container means thereon, saidcontainer means and coupling being removable from said anesthesiamachine and completely disposable, and of such inexpensive constructionas to be expendable.

It is a general object of the present invention to improve anesthesia byreducing the possibility of exposure of patients to cross contaminationfrom equipment employed.

It is an object of the present invention to provide a compact expendablecanister assembly for an absorption anesthesia system.

It is a further object of the present invention to provide a canisterwith protected and versatile fittings for an absorption anesthesiasystem.

Yet another object of the present invention is to provide a circleabsorption anesthesia canister assembly having an expendable couplingincorporating a bleed valve and a pair of one way directional valveswith a titting for receiving a rebreathing bag.

Related objects and advantages of the present invention will be apparentfrom the following description.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a fragmentary perspectiveview of the canister assembly of the present invention mounted to theanesthesia machine.

FIGS. 2 through 4 and 6 and 7 are on a smaller scale than FIG. 1, andFIG. 5 is on a larger scale.

FIG. 2 is a cross-sectional view taken along a line and viewed in thedirection of the arrows 22 of FIG. 1.

FIG. 3 is a cross-sectional view taken along a line and viewed in thedirection of arrows 3- -3 of FIG. 1.

FIG. 4 is a view taken along a line and viewed in the direction ofarrows 4-4 of FIG. 1.

FIG. 5 is side view of the four way coupling shown in FIG. 1 withportions thereof fragmented.

FIG. 6 is a section like FIG. 2 but showing another embodiment.

FIG. 7 is a section like FIG. 3 but showing the embodiment of FIG. 6.

DESCRIPTION OF PREFERRED EMBODIMENTS Referring now more particularly toFIGS. 1 through 5, a portion of an anesthesia machine 11 is shown inFIG. 1 having a bracket 202 on which the canister case 201 is secured bya metal strap 203. Other mountings for the canister might also be used.Just one example is a metal basket mounted on the gas machine 11 andinto which the canister may be dropped. A controlled amount of gas frommachine 11 is provided through hose 12 to a first inlet fitting 200integral with the canister case. The incoming gas flows in the directionof arrows 204 through a first chamber 209 and into a second chamber 210.The gas continues to flow throught the second chamber 210 around end 225of center partition 224 (FIG. 2) in the direction of arrow 205 (FIG. 1)and up into a third chamber 211 in the direction of arrow 206. Apressure indicator 212 mounted to bracket 202 is in communication withchamber 21 1 via a hose 213 connected to the outlet fitting 214 integralwith the canister case. Thus, the gas may flow in the direction of arrow207 through hose 213 to indicator 212. In addition, the gas may flow inthe direction of arrow 208 out through an outlet fitting 215 which isintegrally connected to the canister case. The gas flows through acoupling 217 which is received by fitting 215 and through hose 28connected to the coupling. Face mask 31 is connected to hose 28 and tohose 32 which in turn is connected to a four way coupling 230 receivedby an inlet fitting 218 integral with the canister case. As will bedescribed later in this specification,

coupling 231] has a pair of one way directional valves, a bleed valveand an outlet connected to a rebreathing bag.

FIGS. 2 through 4 are reduced cross-sectional views of the canister caseshown in FIG. 1 with the hoses and coupling shown in FIG. 1 beingdeleted for the sake of clarity. Case 201 is rectangular inconfiguration having a pair of side walls 219 and 220 integrally joinedto end walls 221 and 222 and rear wall 223. Case 201 is produced frommolded plastic and has a separating wall 224 integrally joined to endwall 221 and rear wall 223 and being spaced equidistant from walls 219and 220. The bottom edge 225 of wall 224 is in spaced relationship toend wall 222. A plurality of ridges 227 and 228 are provided on themutually facing surfaces of walls 219, 220 and 224 to receive perforatedwalls 231 and 232. As previously mentioned, it is desirable to selectthe amount of absorbent material within the canister case depending uponthe desired period of time which the canister is to be utilized. Inother words, although it is desirable to manufacture the canister in thesame overall dimensions for virtually all uses, there will be no needfor the complete filling of the canister if the canister is to be usedfor only a comparatively short period of time. Thus, ridges 227 and 228are provided at fixed intervals along the lengths of walls 219, 220 and224 in order that perforated walls 231 and 232 may be installed betweenthe appropriate ridges depending upon the amount of absorbent materialto be provided in chamber 210. The laterally extending and alignedgrooves 229 formed between the laterally extending ridges 227 and 228slidably receive the edges of the perforated walls 231 and 232. Thus inassembling the canister, walls 231 and 232 may be inserted into theappropriate grooves 229 and the absorbent material may then be placedinto chamber 210 with the lid 226 then being fixedly secured to the sidewalls, end walls and separating wall 224 by adhesives or other suitablefastening means.

The longitudinally extending wall 224 in conjunction with the perforatedwalls 231 and 232 separates case 201 into a first chamber 209, a secondchamber 210 and a third chamber 211. Chamber 209 is separated fromchamber 211 by wall 224 which extends partially into chamber 210. Theperforated walls 231 and 232 slidably received in the aligned grooves229 have apertures of a sufficiently small size to prevent passage ofthe absorbent material from chamber 210 to chambers 209 and 211. Ofcourse, the apertures are of a sufficient size so as to allow gas topass therethrough.

FIG. 3 is an enlarged cross-sectional view taken along the line andviewed in the direction of arrows 33 of FIG. 1 illustrating the fittings200 and 218. Fitting 200 has a generally circular recessed wall 234integrally joined to a flat wall 235 provided with an aperture 237extending through stem 238 which is centrally positioned with respect tocircular wall 234. The annular cavity 236 between stem 238 and circularwall 234 is sized to receive hose 12. The gas from hose 12 may therebypass through aperture 237 and through wall 232 in the direction of arrow204. The gas then continues to flow around wall 224 in the direction ofarrow 205 (FIG. 1).

Fitting 218 has a circular slightly tapered wall 239 integrally jointedto lid 226 thereby defining a round cavity 240 which receives thecircular body of four way coupling 230 (FIG. 1). Circular wall 239 hasan inward turned flange portion 242 defining circular opening 241 whichallows gas to pass from cavity 240 into chamber 209. Annular ridge 243is integrally formed with flange portion 242 and surrounds opening 241and can furnish an internal piloting surface for a valve cup, ifdesired.

Fitting 214 (FIG. 4) is identical to fitting 200 having a circular wall244 integrally joined to a flat wall 245. An aperture 247 through wall245 extends through stem 248 with an annular cavity 246 surrounding thestem. It is to be noted that stems 248 and 238 are tapered having asmall outside diameter adjacent to wall 223 and increasing in diameteras the fitting extends into the chambers. These provide a tight fit withrespect to the hoses received. Fitting 215 likewise has a circular wall249 which turns inwardly forming a flange wall portion 250 which isintegrally joined to stem 251. An aperture 252 extends through stem 251allowing gas from chamber 211 to pass outwardly to hose 28 (FIG. 1).Annular cavity 253 is formed between stem 251 and circular wall 249.Ridge 254 is integrally formed with wall 250 surrounding aperture 252,and can furnish an external piloting surface for a valve cup if desired.It is to be noted that the stem of each of the previously desiredfittings as well as the other portions of the fittings do not extend orprotrude beyond the canister case, thereby preventing damage to thefittings during packing and transportation of the canister case. Also itshould be noted that the orientation of the fittings 215 and 218, andthe tapers and draft on the surfaces thereof, are such that the lid,with these fittings thereon, can be simply molded in one piece. The sameis true of the case.

An enlarged fragmentary view of the four way coupling 230 of FIG. 1 isshown in FIG. 5. Coupling 231) may be referred to as a modified teefitting and has a main body 260 with an inlet fitting 261 for receivinghose 32 (FIG. 1). Main body 260 is frictionally and sealingly receivedinto the annular cavity 240 (FIG. 3) of fitting 218 and is fragmented at266 and 267 to illustrate a pair of one way directional valves 264 and265. Valve 264 includes a circular rim with radially inwardly projectingintegral spokes forming a spider 268 integrally joined in a hub 274 atthe center of the spider, with openings provided therebetween to allowthe gas to pass therethrough. The center 274 of spider 268 has aprotrusion 271 receiving a flexible rubber sheet 272 which is securedthereon by cap 273 press fitted onto the protrusion. An annular ridge269 is formed on the rim of spider 268 and serves as a valve seatsealingly receiving sheet 272. Ridge 269 cooperates with sheet 272 toprevent gas flow in the direction of arrow 276 while allowing gas flowin the direction of arrow 275. The rim is adhesively or otherwise sealedentirely around its circumference to the inner wall of body 260.

Valve 265 is similar to valve 264, including a rim, spokes, hub, rubberflapper, flapper mounting stem, and retaining cap on the stem. However,the rim is cup shaped, having the axially extending circular flange265A. Also the cup has a rib 265B extending in a circle around theupstream face of the valve assembly. The cup is sealed by an adhesive orother means around its entire circumference to the main body and isthereby sealed and retained firmly in place. Therefore, one waydirectional valve 265 allows gas flow only in the direction of arrow275. Fitting 262 opens into main body 260 and receives rebreathing bag37.

A bleed valve 263 is provided to allow the gas within main body 260 tocontrollably escape to an external environment. Bleed valve 263 has acap 281 received by fitting 280 communicating with the hollow interiorof main body 260. A stem 282 is integrally connected to the circularlyshaped cap 281 and has a chamber 283 receiving a ball 284. The bottomend 285 of stem 282 is restricted so as to prevent the ball from fallingfrom the chamber. Likewise, a bonnet 286 is received at the top end ofthe stem having an aperture 287 of a sufficiently small size so as toprevent ball 284 from being forced from the chamber as a result of gaspressure. An overcap 289 having an integral plug 290, and internal ribssuch as 291 received in circularly spaced grooves 288 extendinglongitudinally down the outside of cap 281, is normally used, though notshown in FIG. 1.

To use the bleed valve for bleeding some gas from the system, cap 281 ismanually turned on fitting 280 to obtain some registry of an aperture292 in the skirt of cap 281 with a slot 293 in the wall of fitting 280.The shape of the edges of the aperture and slot can be designed asdesired to obtain various rates of attainment of registry of theopenings per degree of turning of the cap. The gas thus vented canescape from under the lower edge of the overcap.

To avoid accumulation of vented gas in the vicinity, a vacuum line canbe employed. For this purpose, a loop 294 is provided on the overcap,and is sized to fittingly receive a vacuum hose. The loop is turneddownward on its integral plastic hinge 295 and the hose end is projectedthrough it to the space 296 to extract from under the overcap 289 allvented gas and discharge it to the exhaust of the vacuum system.

In some instances it may be desirable to bleed gas from the systemthrough the tapered passageway 283. For this purpose, the overcap israised so plug 290 is removed from aperture 287. The friction fit of theribs 291 in grooves 288 will retain the overcap in position with plug290 out of the aperture. Then gas can escape upwardly through passageway283. At higher internal pressures, the ball will be raised further inthe passageway, whose internal diameter increases at increasingdistances from the bottom. If the anesthetist squeezes the rebreathingbag, of course the ball will seat on the edge of the aperture 287,terminating the bleeding and facilitating production of the effectdesired from squeezing the bag.

It was mentioned above that the valve assembly 265 employed the rib 265Bon the upstream face of the cup. Rib 243 in FIG. 3 and rib 254 in FIG. 4were also mentioned. If it is desired to have the valves built directlyinto the canister, valve assemblies like 265 can be employed. At fitting215 (FIG. 4) the cup would be mounted with its rim abutting wall 250 andlocated around rib 254, and adhesively or otherwise secured and sealedaround its circumference at the abutment of the rim with wall 250. Thusit will permit flow only out of the canister at this fitting. At fitting218 (FIG. 3) the cup would be mounted with rib 265B centered within rib243 and adhesively or otherwise secured and sealed around itscircumference at that location. Thus the valve will permit flow onlyinto the canister at this fitting. The outside and inside diameters ofrib 265B of the cup, and rib 254 of the fitting 215 are essentially thesame. Also the outside and inside diameters of the flange 265A at therim of the open end of the cup are essentially the same as they are forrib 243 of fitting 218. Therefore, if an attempt were made to installthe cups in the wrong direction on the respective fittings there wouldbe no mating of the cups to the fittings, and the error would beimmediately noticed and corrected.

Referring now to FIGS. 6 and 7, note that in this embodiment theperforated partitions 231 and 232 of the previous embodiment are absentfrom the grooves on the walls. Instead there are perforated partitions296 and 297, both inclined as best shown in FIG. '7. One or more buttonsor a ledge can be provided on the inner face of wall 223 as shown at 298to support the upper edge of each of the partitions. The upper ribs 227of the walls 219, 220 and 224 can support the lower portion of thepartitions. This of course does not show in FIG. 6 because the locationof the section plane is the same as that for FIG. 2. The partitions canbe adhesively or otherwise sealed to the walls of the canister, ifdesired, prior to installation of the cover.

Some benefits derived from the sloped upper partitions are increasedavailable space for absorbent material, facility of filling withabsorbent material, desirable gas flow distribution through absorbentmaterial. Of course additional perforated partitions can be employed ifand where desired between the various sets of ribs 227. Also, ifdesired, the inclined partitions can be employed in a unit having anadditional pair of perforated partitions, one on each side of wall 224and in the upper grooves, as shown in FIG. 2 for partition 231 and 232,or in lower grooves, with the additional partitions serving to confinethe absorber material, leaving free space between the additionalpartition and the inclined partitions. When a full volume of absorbentmaterial is filled completely to the inclined partition, the particlesare normally larger than the ID. of the apertures in fittings 200 and214, and are not likely to clog them. If believed necessary ordesirable, a fiberglas gauze or filter material can be employed in theapertures.

It may be observed from the drawings that the entire case, includinglid, is made of a transparent plastic.- This is true also of thefour-way coupling. Therefore the interior as well as exterior of theentire unit can be observed during use. Also the shape of the case andlocation of fittings and shape and placement thereof, and the tapers anddraft of the surfaces involved facilitate molding thereof in one piece.The same is true of the lid, and the plastic portions of the valveassemblies. Because the plastic is expendable, all of this contributessignificantly to low cost whereby the entire canister and four-waycoupling are expendable, and can be discarded after use with a singlepatient.

Perhaps it should be mentioned that, while the chamber below theperforated partitions FIGS. FIG. 1 through 4 and 6 and 7 are shown withonly a comparatively few particles of absorbent material therein, thisis for convenience of illustration of other features of the unit, and itshould be understood that wherever the particles are shown, the chamberis actually filled with the absorbent material.

In the use of the equipment, because of the low cost, and because of thevarious possibilities for absorbent material capacity with-in canistersof a standardized size, where anesthesia will be needed for an extendedperiod on an adult patient of large lung capacity, a canisterpartitioned for maximum volume of absorber material may be used. Afteranesthesia, the entire circle absorption system may be discardedeconomically, in-

cluding not only the hoses, rebreathing bag, and face mask, but also thefour-way coupling and valve assembly, and canister. A new system may beassembled for the next patient and may employ a canister with theperforated partitions located such that the canister is filled to alesser volume with absorbent material, depending on the needed durationof the anesthesia and the size of the patient. While possible, it is notintended that the canister be filled at the site of use, but rather thata more practical approach is to stock pre-filled and sealed canisters,filled with various volumes of absorbent material depending uponanticipated patient requirements.

Incorporation of the valves in a separable coupling member as shown inFIGS. 1 and 5, and which can be friction fitted into and removed fromfitting 218 in a succession of canisters, makes possible the use of thisvalve coupling with several patients in succession if desired, eventhough a different canister is used for each patient. The valvedcoupling may be succeptible to certain sterilization technique makingits re-use completely safe. However it is contemplated and preferredthat the entire circle system of FIG. 1 be assembled of new parts foreach patient in succession, and discarded after use with that patient.Naturally the gas machine would not be discarded, nor is it likely thatthe pressure gauge or mounting bracket would be discarded. While theinvention has been illustrated and described in detail in the drawingsand foregoing description, the same is to be considered as illustrativeand not restrictive in character, it being understood that only thepreferred embodiments have been shown and described and that all changesand modifications that come within the spirit of the invention aredesired to be protected.

The invention claimed is:

1. The combination comprising:

container means including a rectangular case having partition meanstherein and a lid cooperating with said partition means to define first,second, and third chambers in said case, said second chamber beingadjacent to said first and third chambers, a first inlet fitting in saidcontainer means communicating with said first chamber, a first outletfitting in said container means communicating with said third chamber,an absorbent material for carbon dioxide disposed in said secondchamber, and said first chamber being isolated in said case with respectto said third chamber except for communication through said absorbentmaterial in said second chamber, said fittings being recessed;

additional apertured fittings in said container means communicating withat least one of said chambers therein;

said additional fittings being disposed on a wall opposite said inletand outlet fittings, said fittings having parallel axes.

2. The combination of claim 1 wherein at least three of said fittingsinclude apertured stems outwardly directed with respect to saidcontainer means but terrninating substantially in alignment with therespective walls on which said fittings are disposed.

3. The combination comprising:

container means including a rectangular case having partition meanstherein and a lid cooperating with said partition means to define first,second, and third chambers in said case, said second chamber beingadjacent to said first and third chambers, a first inlet fitting in saidcontainer means communicating with said first chamber, a first outletfitting in said container means communicating with said third chamber,an absorbent material for carbon dioxide disposed in said secondchamber, and said first chamber being isolated in said case with respectto said third chamber except for communication through said absorbentmaterial in said second chamber, said fittings being recessed;

a four way coupling mounted to said second inlet fitting, said couplinghaving a fourth chamber with a one way inlet fitting allowing gas topass only in a direction into said fourth chamber, said coupling havinga one way outlet fitting allowing the gas to pass from said fourthchamber into said first chamher, said coupling having a gas bag fittingand a bleed valve.

1. The combination comprising: container means including a rectangularcase having partition means therein and a lid cooperating with saidpartition means to define first, second, and third chambers in saidcase, said second chamber being adjacent to said first and thirdchambers, a first inlet fitting in said contaiNer means communicatingwith said first chamber, a first outlet fitting in said container meanscommunicating with said third chamber, an absorbent material for carbondioxide disposed in said second chamber, and said first chamber beingisolated in said case with respect to said third chamber except forcommunication through said absorbent material in said second chamber,said fittings being recessed; additional apertured fittings in saidcontainer means communicating with at least one of said chamberstherein; said additional fittings being disposed on a wall opposite saidinlet and outlet fittings, said fittings having parallel axes.
 2. Thecombination of claim 1 wherein at least three of said fittings includeapertured stems outwardly directed with respect to said container meansbut terminating substantially in alignment with the respective walls onwhich said fittings are disposed.
 3. The combination comprising:container means including a rectangular case having partition meanstherein and a lid cooperating with said partition means to define first,second, and third chambers in said case, said second chamber beingadjacent to said first and third chambers, a first inlet fitting in saidcontainer means communicating with said first chamber, a first outletfitting in said container means communicating with said third chamber,an absorbent material for carbon dioxide disposed in said secondchamber, and said first chamber being isolated in said case with respectto said third chamber except for communication through said absorbentmaterial in said second chamber, said fittings being recessed; a fourway coupling mounted to said second inlet fitting, said coupling havinga fourth chamber with a one way inlet fitting allowing gas to pass onlyin a direction into said fourth chamber, said coupling having a one wayoutlet fitting allowing the gas to pass from said fourth chamber intosaid first chamber, said coupling having a gas bag fitting and a bleedvalve.